There are some game contents provided to a user where advertisements are displayed on the screen during game play. For example, a real advertisement is posted as a texture on a billboard of a race course in a car racing game, and a product advertisement is displayed on a billboard in a virtual space where a character explores.
An advertisement that is inserted in such a game space is usually made by a game soft company, which is the creator of the contents, at the request of an advertiser. It is provided in an optical disk such as a CD or a DVD as texture data of the advertisement along with the program data of a game. When a user starts a game by using a personal computer or a home game terminal after purchasing an optical disk that stores the game contents, the advertisement is displayed on an object such as a billboard in the game space.
A patent document 1 discloses a technique for displaying an advertisement during game play by posting it as a texture, and a patent document 2 discloses a system where advertisement information assigned in advance is inserted when a user starts the downloaded contents, and then where the advertisement information is displayed at a corresponding position while the contents are running.    [Patent document 1] JP 9-10440    [Patent document 2] JP 2002-83219